A sensitive and selective procedure for the voltammetric determination of brilliant indigo and acid yellow 23 at surfactant modified graphene paste electrode

The voltammetric response of brilliant indigo and acid yellow 23 on the surface of graphene paste electrode modified with nonionic surfactant was studied in the buffer media at different pH by cyclic voltammetry and differential pulse voltammetry Vs. saturated calomel electrode. Cyclic voltammograms were recorded in the potential range from 0 V to 0.8 V for brilliant indigo, and 0.60 to 1.2 V for acid yellow 23 shows reversible and irreversible response respectively. The developed electrochemical sensor shows good electrocatalytic activity to the oxidation of brilliant indigo and acid yellow 23 by giving elevated peak current than those obtained for the bare electrode. At the optimized conditions, the anodic peak current of brilliant indigo and acid yellow 23 proportional to the concentration ranges from 3.5×10^-6 - 1.5×10^-5 M and 1×10^-5 - 6×10^-5 M with the limit of detection of 0.24 μM and 0.25 μM. The proposed method offers rapid, simple, selective, and cost-effective analysis. Also, this developed electrode exhibited good selectivity, stability, repeatability, and has been successfully used to determine the real sample with a satisfactory result.